1. Field of the Invention
The present invention relates to a submount, optical module, and optical module manufacturing method by which the processes of temporary wiring, gripping and aligning when using active alignment to mount optical components such as laser diodes (LD) or photo diodes (PD) can be carried out with ease.
2. Description of Related Art
When mounting optical components like laser diodes (LD), photo diodes (PD), etc., to form an optical module such as an optical transmitting or optical receiving module, deviations of even a few micrometers can give rise to loss of the signal light. Accordingly, this process demands a highly accurate mounting technique. It has been established that marker mounting using the passive alignment method to mount optical components onto a PLC platform enables mounting with high positional accuracy and good reproducibility, and makes it possible to realize uniform optical coupling with the optical guided wave path (see, for example: Toshikazu Hashimoto, et al, A hybrid integration of a laser diode and a monitor photo diode on a PLC Platform with the passive alignment method, 1996 Institute of Electronics, Information and Communication Engineers General Conference C-206, P206; Seimi Sasaki et al, Passive alignment of LD chip on PLC platform using marker method, 1996 Institute of Electronics, Information and Communication Engineers Electronics Society Conference C-201, P201; Naoki Kitamura et al, Silica-based Planar Lightwave Circuit for passive alignment of LD and optical fiber, 1997 Institute of Electronics, Information and Communication Engineers, Electronics Society Conference C-3-98, P207).
In the aforementioned passive alignment mounting method, each part must be formed with a high degree of accuracy by, for example, forming a chip mounting bench or using etching to highly accurately carve a V-groove in a silicon substrate, etc., and then carrying out positioning using alignment marks. In order to carry out this passive alignment, extremely accurate component processing is required. However, despite the high cost that is required for this type of component processing, high accuracy often is not obtained, leading to a drop in output and sensitivity, and extremely poor yields.
The use of active alignment, which does not have the problems associated with component accuracy, may be considered in place of passive alignment. In active alignment, alignment is carried out by powering up the components in the device before fixing them in place. Therefore, it is necessary to provide wiring to the optical components. However, wire bonding or die bonding is used for the wiring for driving the optical components, and is therefore performed after the components have been fixed in place. Accordingly, active alignment in which alignment is performed by powering the optical components cannot be performed in this case.